uses crt;
var a:array[1..100] of integer;
i,n,x,y,s:integer;
begin
clrscr;
write('nhap so luong phan tu:');readln(n);
for i:=1 to n do
begin
write('nhap phan tu thu ',i,': '); readln(a[i]);
end;
for i:=1 to n do
if a[i]=0 then y:=i;
for i:=n downto 1 do
if a[i]=0 then x:=i;
for i:=x to y do s:=s+a[i];
write('Tong la: ',s);
readln;
end.

uses crt;
var i,n,b,d,c,s:integer;
a:array[1..100] of integer;
begin
clrscr;
write('nhap so ptu:');readln(n);
for i:=1 to n do
begin
 write('a[',i,']=');
 readln(a[i]);
 if a[i] =0 then d:=d+1;
end;
while d<2 do
begin
d:=0;
writeln('ko du so 0 nhap lai');
for i:=1 to n do
begin
 write('A[',i,']=');
 readln(a[i]);
 if a[i]=0 then d:=d+1;
end;end;
for i:=1 to n do
 if a[i] =0 then c:=i;
for i:=n downto 1 do
 if a[i] =0 then b:=i;
for i:=b to c do s:=s+a[i];
write('tong cac ptu tu nam giua so 0 dau tien va so 0 cuoi cung la:',s);
readln;
end.

(mong dc 5*+hay nhất)